1. Field of the Invention
The present invention relates to a method for the preservation of blood and to a useful blood preserving composition. More particularly, the invention relates to the preservation of blood by incorporating a phosphoric acid diester of ascorbic acid and tocopherol, or a pharmacologically acceptable salt thereof.
2. Description of the Prior Art
Blood consists of formed elements such as erythrocytes, leukocytes and platelets and plasma which is the liquid component in which the formed elements are contained. Blood is a vital medium for the life of the body cells and its properties remain almost constant. In the meantime, during surgery and in other cases, the transfusion of blood or its components is oftentimes required. The biological functions of blood or its components must be maintained while in storage and until the transfusion is accomplished. It is also of importance to prevent functional disorders such as hepatic disorder, which can sometimes accompany blood transfusion.
As employed herein, the term "blood" is intended to encompass not only "whole" blood but also its component parts as indicated above.
Compositions for preserving blood have been previously known. For these purposes, there have chiefly been used sugars as an energy source, inorganic salts as agents for adjusting pH and osmotic pressure, and adenine as an agent for preventing consumption of blood ATP (adenosine triphosphate), ADP (adenosine diphosphate) and AMP (adenosine monophosphate). However, these blood preserving compositions are hardly satisfactory because they cannot fully maintain blood ATP level which is an index of life for the haemocyte components and because they do not have a satisfactory preventive activity against hepatic disorders which have been associated with blood transfusion.
Accordingly, blood preserving compositions which have a superior blood preserving action and preventive activity against potential hepatic disorders after blood transfusion are presently under study.
Under the circumstances, the inventors of the present invention have searched for compounds having potent blood preserving activity and have found that a phosphoric acid diester of ascorbic acid and tocopherol and pharmacologically acceptable salts thereof have a potent blood preserving action. Based on the above finding, the present invention has been completed.